A medical worker collects a swab sample for nucleic acid test in Ruili City of southwest China's Yunnan Province, on July 5, 2021. Ruili City on Monday imposed entry and exit restrictions after the emergence of new COVID-19 cases. The city reported three new locally transmitted confirmed COVID-19 cases on Sunday. Authorities have asked people to refrain from entering or leaving the city unless necessary. (Xinhua/Wang Guansen)
